1. What is the Foot-Pounds Calculation?

The Foot-Pounds calculation measures the kinetic energy of a projectile based on its weight and velocity. It's commonly used in ballistics to compare the stopping power of different ammunition types.

2. How Does the Calculator Work?

The calculator uses the Foot-Pounds formula:

Where:

• \( Weight \) — Projectile weight in grains
• \( Velocity \) — Projectile velocity in feet per second (fps)
• 450240 — Conversion factor (2 × gravitational acceleration × 7000 grains per pound)

Explanation: The equation calculates kinetic energy by accounting for both the mass and velocity of the projectile, with velocity being squared to reflect its greater importance in energy calculation.

3. Importance of Foot-Pounds Calculation

Details: Foot-pounds energy is crucial for understanding a projectile's potential impact, effectiveness for hunting, and penetration capability. It helps compare different ammunition types objectively.

4. Using the Calculator

Tips: Enter weight in grains (1 grain = 1/7000 pound) and velocity in feet per second. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why use grains instead of ounces or grams?
A: Grains are the standard unit for measuring bullet weight in ballistics (1 grain = 64.79891 milligrams).

Q2: What's a typical foot-pounds value for hunting?
A: Minimum recommendations vary by game: 1000 ft-lbs for deer, 1500 ft-lbs for elk, and 2000+ ft-lbs for large/dangerous game.

Q3: How does velocity affect energy more than weight?
A: Since velocity is squared in the equation, doubling velocity quadruples energy, while doubling weight only doubles energy.

Q4: What's the 450240 constant derived from?
A: It comes from (2 × 32.174 ft/s² × 7000 grains/lb) - converting grains to pounds and accounting for gravitational acceleration.

Q5: Can I use this for arrows or other projectiles?
A: Yes, the formula works for any projectile when you know its weight in grains and velocity in fps.